1. Field of the Invention
The present invention relates to a digital information signal recording apparatus for recording a digital information signal such as a digital video signal and/or a digital audio signal to a record medium and to a reproducing apparatus for reproducing a digital information signal from a record medium.
2. Description of the Related Art
A signal processing apparatus that digitally processes a video signal (for example, a signal processing apparatus for use with a digital VTR (Video Tape Recorder) that records/reproduces a high resolution video signal) performs a picture compressing and encoding process for an input picture signal. The compressed and encoded video signal is recorded to for example a video tape.
With two digital VTRs, a signal reproduced by one VTR is recorded to a tape by the other VTR (namely, a dubbing process is performed). There are the following two dubbing methods. In the first dubbing method, after the amplitude, offset, and so forth of a reproduced video signal are processed, the resultant signal is recorded. In the second dubbing method, a reproduced signal is recorded without any process. Hereinafter, the first dubbing method is referred to as normal dubbing method (operation), whereas the second dubbing method is referred to as straight dubbing method (operation).
With conventional digital VTRs, the same terminal is used regardless of whether the normal dubbing process or the straight dubbing process is performed. In VTRs that compress/expand a picture signal, the reproducing VTR expands the picture signal and sends the resultant signal to the recording VTR. The recording VTR compresses the picture signal and then records the resultant signal to a tape. Generally, when a picture signal is compressed/expanded, it is difficult to completely restore the original signal. In other words, the original signal unavoidably deteriorates. Thus, even in the straight dubbing process, when it is repeated, the picture quality deteriorates.
Thus, an object of the present invention is to provide a digital information recording apparatus and a reproducing apparatus that suppress a signal that is dubbed from deteriorating.
To solve the above-described problem, the present invention is a digital information signal recording apparatus for recording a digital information signal to a record medium, comprising:
a first input terminal for inputting a digital information signal;
a first encoder for performing a compressing process for the digital information signal that is input through said first terminal;
a second encoder for performing an error correction code encoding process for a compressed signal received from said first encoder;
recording means for recording an output signal of said second encoder to a record medium; and
a second input terminal for inputting data that has been compressed.
To solve the above-described problem, the present invention is a digital information signal reproducing apparatus for reproducing a digital information signal from a record medium, comprising:
reproducing means for reproducing a signal from a record medium;
a second decoder for performing an error correction code decoding process for a reproduced signal that is input from said reproducing means;
a first decoder for performing a decompressing process for an output signal of said second decoder;
a first output terminal for outputting a reproduced signal decompressed by said first decoder; and
a second output terminal for outputting a reproduced and compressed signal that has not been not been decompressed by said first decoder.
The present invention is a data transmitting method for transmitting compressed data between an apparatus for reproducing a digital information signal from a record medium and an apparatus for recording a digital information signal to a record medium, comprising the step of:
providing compressed data with a portion for the error flag for each record/reproduction data block.
According to the present invention, since a terminal for a compressed signal of which a picture-compressing/expanding process is not performed is disposed, in the straight dubbing process, the deterioration of a picture quality can be minimized. In addition, since a terminal for the straight dubbing process (this terminal may be sometimes referred to straight dubbing terminal) is disposed, while the normal reproducing process is being performed, the straight dubbing process can be performed. Moreover, with a format of a signal sent through the terminal for the straight dubbing process, error information of data reproduced from a tape is sent. In addition, error information that takes place on a transmission path is left on a tape. Thus, the deterioration of the picture quality can be further suppressed.
The above, and other, objects, features and advantage of the present invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings.